/**
 * Copyright (C) 2015 The Gravitee team (http://gravitee.io)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package io.gravitee.am.common.oauth2;

import java.util.Arrays;
import java.util.List;

/**
 * See <a href="https://tools.ietf.org/html/rfc7636#section-4.2>4.2. Client Creates the Code Challenge</a>
 *
 * @author Titouan COMPIEGNE (titouan.compiegne at graviteesource.com)
 * @author GraviteeSource Team
 */
public interface CodeChallengeMethod {

    /**
     * code_challenge = code_verifier
     */
    String PLAIN = "plain";

    /**
     * code_challenge = BASE64URL-ENCODE(SHA256(ASCII(code_verifier)))
     */
    String S256 = "S256";

    static List<String> supportedValues() {
        return Arrays.asList(PLAIN, S256);
    }
}
